1. Field of the Invention
This invention relates to new phosphonic acid esters and to cosmetic hair treatment preparations containing them as additives for improving the wet combability of hair.
2. Description of Related Art
After washing with shampoos based on synthetic surfactants, the hair of the head is often in a cosmetically unsatisfactory condition. It feels dull and is difficult to comb when wet. After drying, the washed hair tends to develop a static charge which makes combing difficult and spoils the set of the combed hair.
It is known that conditioning preparations may be applied to hair after washing or shampooing. Such preparations are mostly gel-like, liquid, or emulsion-like lotions containing cationic surfactants. It is also known that certain substances may be added to normal shampoos to obtain a certain conditioning effect when the hair is washed. Examples of these substances are, for example, water-soluble proteins, protein degradation products or polycationic polymers, for example cationic cellulose derivatives. The disadvantage of cationic surfactants lies in their inadequate compatibility with anionic surfactants and their often unsatisfactory compatibility with the mucosa.
Polycationic polymers do not counteract the static charging of dry hair and, in many cases, actually increase the static charging of hair. On the other hand, the strong adsorption of these cationic polymers to the keratin fibers, particularly in the event of repeated applications, results in an accumulation of the polymers on the hair which is thus "burdened" and loses elasticity, set and body. Accordingly, there is a need for hair treatment preparations which contain additives improving the wet combability of hair and which are affected by the above-mentioned disadvantages to a lesser extent, if at all.